The present invention relates to liquid organic solvents.
Organic solvents are useful as cleaners in high technological industries, such as the aerospace and electronic industry, as well as in every day applications encountered in the typical household. Solvent cleaning is currently accomplished using a variety of highly or modrately toxic solvents. Because of the growing concern for personal safety, personal health and the environment, both the federal and state governments are promulgating increasingly stringent criteria which solvent manufacturers and users must comply with to ensure the health and safety of those working with and around such solvents. For instance, the California state legislature limits the use of volatile solvents by requiring that they have a vapor pressure below about 45 mm Hg at 20.degree. C. In addition, environmental concerns and regulations require that such solvents be disposed of in a manner that will not adversely affect the environment. For many users of such solvents, this disposal generally translates into increased operating costs.
A primary consideration to the user of an organic solvent is the toxicity of the components making up the solvent mixture. Although personal safety can be promoted primarily by preventing direct contact and exposure to such solvents by not exceeding published threshold values, such generalized policies do not take into consideration individual sensitivities or the possibility of an accidental exposure to amounts in excess of the threshold values. The flammability, volatility, cleaning ability, stability during storage, and odor are other factors that are considered by the user in choosing a particular solvent. One solvent that has found widespread application in industrial applications, such as the aerospace industry, is methylethylketone (MEK). Although MEK is generally considered a satisfactory solvent from a cleaning effectiveness standpoint, there is a growing concern that the toxicity and flammability of MEK exposes users to unnecessary risks. Moreover, the expense associated with the safe disposal of MEK is 5 to 10 times greater than the amount the user initially pays for the MEK.
Therefore, increasing efforts are being devoted to developing substantially nontoxic solvents that exhibit low flammability, superior cleaning ability, have a pleasant odor, and are stable during storage. Such solvents will be safe to use not only in large scale industrial applications, but also on the much smaller scale encountered in every day household cleaning chores.